*2.9. Antioxidant Activity of Films*

Antioxidant activity values of all the tested films were measured following the diphenyl-1-picrylhydrazyl (DPPH) assay method and are listed in Table 3.


**Table 3.** Antioxidant activity of all obtained films.

It is already known that Sodium alginate exhibits antioxidant activity [46,47]. According to our measurements, the antioxidant activity of the pure ALG/G film was 8.7%. In the case of NZ incorporation into the polymer matrix, this activity was increased by the addition of 10 %wt. material and over. According to literature, NZ acts as an antioxidant agent due to the entrapment of free radicals in its porous [48]. The microporosity presence in the NZ pore structure enhances the adsorption properties of this material and consequently the antioxidant activity [49]. Thus, the increased antioxidant activity of the NZ containing films measured in this study could be attributed to the adsorption of DPPH ions and free radicals in its structure. According to Table 3 values, even the lower TO@NZ load exhibits stronger antioxidant activity compared to the relevant value of the film with the higher NZ content. This happens because essential oils and especially TO exhibit significant antioxidant activity [50]. As an overall conclusion, we could say that, based on Table 3 values, ALG/G/15TO@NZ films show the highest antioxidant activity.
